feat(ios): run the statement at the cursor in the query editor

[datlechin]

Summary

• Run in the iOS query editor sends the statement at the cursor, or the selection when there is one. Same rule as the Mac: the scanner's statement with its ;, never comment-only text.
• A faint band marks the statement Run will send. A selection hides it.
• Run is a pull-down button. Touch and hold shows Run Statement (Run Selection with a selection) and Run All Statements. Run All Statements is also in the More menu.
• Hardware keyboard: Cmd+Return runs at the cursor, Cmd+Shift+Return runs all, Cmd+. stops. A key-command run keeps the keyboard up.
• Cursor outside any statement: Run keeps the last result and shows "The cursor is not in a statement."
• Safe Mode, Confirm Writes, History and the Live Activity get the text that runs, not the whole editor.
• SQL Server runs the statement at the cursor, as the Mac does, not the whole GO batch.
• Redis: a command ends at a ; or a line break outside quotes. On main, GET a and GET b on two lines ran as GET a GET b, and Safe Mode read only the first verb.
• Redis: a command with an unclosed quote fails instead of storing a cut value.
• Run no longer resigns the editor inside a SwiftUI view update. On main, Run tapped with the keyboard up looped at 100% CPU (AttributeGraph cycle) on the iOS 27 simulator with UI automation attached.
• QueryScriptTests.redisIsOneCommand pinned the old Redis behavior and is replaced by redisSplitsIntoCommands.

Test plan

• New, fail on main: QueryRunTargetTests, RedisCommandSplitterTests, SQLEditorHandleTests, QueryScriptTests.redisSplitsIntoCommands and redisTrimKeepsAnEscapedBlank, SQLWriteClassifierTests.redisWriteInALaterCommand, RedisCommandParsingTests.unclosedQuoteGivesNil, escapedLineBreakMatchesSplitter and escapedTrailingBlankReachesTheDriver. QueryEditorViewModelTests still pass.
• iPhone 18 Pro simulator, Chinook sample, SELECT 1 AS a; / SELECT 2 AS b; / SELECT 3 AS c;, cursor on line 2: main runs all three and shows c = 3, this branch runs line 2 and shows b = 2.
• Touch and hold on Run with SELECT selected shows Run Selection and runs the selection. Cursor after the last statement: the result stays and the note shows.
• Not driven: the hardware keyboard shortcuts (the simulator driver sends no key chords).

	Light	Dark
Before
After
Run menu

Not in this PR

• The Mac reads Redis lines without ; as one command, the same defect fixed here for iOS (databases/redis.mdx example).
• The iOS Redis parser drifts from the Mac's RedisArgumentCodec escapes: a lone trailing backslash (DEL victim\) is dropped on iOS and kept on the Mac.
• A template insert or a History tap replaces the editor text without asking. History entries now hold the text that ran, which makes the History case likelier. .onDisappear drops the pending query save.
• No Query menu in the iPadOS menu bar.

Fixes #3632